Feed-water connection to boiler drum



Oct. 30, 1945. w. s. PATTERSON ET AL I FEED WATER CONNECTION TO BOILERDRUM Filed May 8, 1945 2 Sheets-Sheet l INVENTOR5 Ward ijizl/msan BYJulian tlfiarflzs HTTJRNEY Oct. 30, 1945. w. s. PATTERSON ETAL FEEDWATER CONNECTION TO BOILER DRUM Filed May 8, 1943 2 Sheets-Sheet 2INVENTORS Ward J. Yul/arson BY Julian Liar/mi Patented Oct. 30, 1945UNITED STATES PATENT OFFICE-Y FEED-WATER coNNEcnoN 'ro BoILER DRUM Ward.8. 'Pattersornlchappaqua, and Julian L.

Barnes; Yonkers, N. Y, assignors to Combustion Engineering Company,Inc., New York,

Application May .8. 1943, Seriai .No. 486,124 8 Claims. (Cl. lea- 365)This invention relates to tubular connections to fluid containingvessels and particularly to improvements in tubular connections thr ughwhic a cold fluid flows into .a. vessel containing a relatively hotterfluid, such as the connection for introducing feed water into the drumcontainin saturated steam and water in a steam boiler.

It is recognized that where .a tube enters a drum carrying fluid at adi-fieren-t temperature than that within the drum, special :means shouldbe provided to prevent the .direct contact of the tube with the drumshell at its place of entry. For example, where a tube carryingcoldliquid is rolled directly into a tube hole in .a drum contaminghot'iiguid the tube temperature would pproach that of the fluid flowingtheretlmough while the temperature of the dough at the Joint tends toapproach thatof the hotter fluid w i-thin. The. resulting difierences inexpansion cause the Joint to leak. With great changes -temper tureinjurious internal stresses may o cur within the drum metal near theJoint. For this reason it has also been found desinable to avoidpermitting a mass of fluid of a difie ent temperature than that of thedrum to directlycontaot the drum in .a l cally restricted area,

n bject of this invention is to provide an improved connection betweenatube and :a vessel each of which is subjectto difierent tempera tures,whereby the metal at the joint is main tained at a substantiallyuniform. temperature which is substantially equal to that of the vesselby being contacted by a current of fluid of uniform and propertemperature.

In the accompanying drawings: Figures 1 2 3, 3d, 4 and 5 are vertical-.s.ec tional views through the steam and water drum ofa steamboiler,taken on the center line ofatube connection, and represent differentforms of the invention. r

Referring first to Figure the steam and water drum 1 of a boiler isprovided with .a feed water pipe 2 passing freel into the drum through aSurrOundjng tube 3 iastened to the drum y rolling or weldin into tubehole 4.. Tubes 2 and 3 are preferabl .iastened together by sealing means5 at a location outside of .andspaced irom the drum. In Figure 2 a thirdtube fispacedirom tube 3 and fitting closely about p pe 2 is com nestedthereto at its inner end ata point to Withi the drum The outer ends oftubes and .6 are fastened and sealed at 6.1). Inb t forms t e feed waternine .2 is surround by an 1 space 1 between it and the tube that isfastened to the druml. V

In Figure 1 a connection 9 is made near the outer end of the annularspace between tubes .2 and; for introducing the steam and water mixturedischarging from one or more risers ii of a steam generating boiler. Thetemperature of e steam-water mixture entering through conneotion 9 issubstantially equal to that of the steam and water within the drum I sothat the water flowin through the annular space 1. be tween tubes 2 and3 maintain the joint 4 between tube 3 and the drum shell 1 atsubstantially the temperature of the steam and water within the drum,thereby avoiding the difficulties produced by expansion and temperaturestresses.

In Figure 3a the fragmentary longitudinal section shows a multiplicityof' feed water connections 2, 3 like'theone shown in Figure 3 intransverse section; these are arranged in alignment longitudinally of.the drum. To provide a common connection for water at the temperatureof the saturated steam Within the drum a space or compartment L0 isformed longitudinally of the drum above a box H below the inner surfacat the top of the shell I, the space It being sealed from the interiorof the drum'along its longitudinal and end edges a at l2. One or moreconnections 9 discharge the steam and water mixture from the generatingtubes 8 into the space or compartment 10 above box 1 1 From compartmentI u the water flows outwardly into the annularspace 1 between tubes 3and pipe 2 and thence inwardly through the open end of tube l3 and viathe annular space between it and tube 2 discharging into the box II fromwhich the water may be conducted to other apparatus within the drum,such as a steam and Water separator or a steam purifier. In the absenceof 'box I] the water would discharge directly into drum 1 from tubes l3.

In Fig. a a compartment I0 similar to that of Fig. 3 is provided butlocated at the bottom of the drum beneath the water level; Thiscompartment may cover a large sector at the bottom so as to protectjthebottom locally against cooler ,feed

water coming into contact with the drum shell and the tube joints. Thewater supply pipe '9 from the steam generating tubes may be providedwith a restricted orifice L5 in order to limit the rate of flow, thepurpose of which will be explained later. The water from compartment 111flows downwardly through the annular space '1 around tube It and thenceupwardly into the drum through the annular space I 4 between tubes :13and 2..

In Fig. '5 also the feed .water connection is lodownwardly through theannular space 6 between" tubes 3 and I3 and thence upwardly through thelatter at 1 around pipe 2 because of the ejector action of nozzle [6 andVenturi throat I! and mixed with the jet of water from nozzle l6. anddischarged therewith through throat 7 l1 and thence into the boilerdrum.

The invention is particularly applicable to a forced circulation boilerin which parallel boiler tube circuits are each provided with restrictedorifices, or resistances, for the purpose of insuring an adequate flowof water through each and all circuits. In Fig. 1 one of the boiler tubecircuits 8 between the circulation pump discharge header and the steama'ndwater' drum is directed into the annular space between pipe 2 andtube 3.' In Figs; Sand 4 one or more of said circuits 8 are directedinto the compartment [0. Should a directly connected tube be providedbetween the circulation pump and the compartment I0, a restrictingorifice or a resistance l5, as shown in Fig. f1, may be introduced intothe circuit soas to balance its resistance with that of the remainingboiler tube circuits which discharge directly into the steam and waterdrum.

What we claim is: v 1. In a vessel containing a heated liquid having anouter. tube fastened to the vessel and open at one end to the interiorof the vessel, a tube for supplying a cold liquid to the vesselprojecting through the. outer tube and spaced from said outer tube toform an annular passage therebetween and means for fastening and sealingthe inner to the outer tube at a point outside of and spaced from thevessel; and pump means for continuously supplying a positive current ofliquid at a temperature substantially that'of the liquid in thevessel tosaid annular passage.

. 2. In a vessel containing a. heated liquid, an outer tube fastened tothe vessel and open at one end to the interior of the vessel, a tube forsupplying a .cold liquid to the vessel projecting through the outer tubeand spaced from said outer tube to form an annularpassage therebetweenandmeans for fastening and sealing theinner to the outer tube at a pointoutside of and spaced from the vessel; a third tube concentricallydisposed intermediate the inner and outer tubes and spaced therefromwith one end open thereof ad- 'jacent the seal between said tubes andits other end extending into and open to the drum interior; and pumpmeans for causing a continuous current of liquid of a temperaturesubstantially equal to that of the liquid within said drum to flowpositively through the annular passage between the outer andintermediate tubes and thence between the intermediate and inner tubes.a

3. In a vessel containing a heated fluid having an outer tube fastenedto the vessel and open at one end to the interior of the vessel, a tubefor supplying a cold liquid to the vessel projecting through the outertube and spaced from said outer tube to form an annular passagetherebetween and means for fastening and sealingthe inner to the outertube at a point outside ofand spaced from' the vessel; a third tubeconcentri- The boiler water flows cally disposed intermediate the innerand outer tubes and spaced therefrom with one end open thereof adjacentthe seal between said tubes and its other end extending into and open tothe drum interior; and pump means for continuously causing apositive..currentof the liquid from within the drum to flow through theannular. passage between "the outer and intermediate tubes and thencebetween the intermediate and inner tubes.

4. In a vessel containing a heated liquid; an outer tube fastened to thevessel and open at one end to the interior of the vessel; partitionswithin the drumsealed to its walls to form a chamber closed off from theremainder of the vessel; a tube for supplying a cold liquid to thevessel projecting through said chamber and the outer tube. to dischargeinto said vessel and spaced from said outer tube to form an annularpassage therebetween; means for fastening and sealing the inner to theouter tube at a point outside of and spaced from the vessel; a thirdtube concentrically disposed intermediate the inner and outer tubes andspaced therefrom with one end open thereof adjacent the seal betweensaid tubes and its other end extending through said chamher into andopen to the drum interior; a liquid delivery tube connecting into saidchamber; and pump means for'continuously causing a positive current ofliquid to flow into the chamber to pass thence sequentially through theannular passage between the outer and intermediate tubes and between theintermediate and inner tubesto the interior of the vessel.

5; In a vessel containing a heated fluid having an outer tube fastenedtothe vessel and open at one end to the interior of the vessel, a tube forsupplying a cold fluid to the vessel rojecting through the outer tubeand spaced from said outer tube to form an annular passage therebetweenand means for fastening and sealing the inner to the outer tube at apoint outside of and spaced from the vessel; a third tube concentricallydisposed intermediate the inner and outer tubes and spaced therefromwith one end open thereof adjacent the seal between said tubes and itsother end extending into and open'to the drum interior, a portion ofsaid intermediate tube being formed into a Venturi throat; and a nozzleon the end of the inner positioned tube to discharge into the throatwhereby a flow of fluid from the drum is induced to flow through theannular Passage between the tubes by the 'jet of fluid from the nozzle.

6. In a vessel containing heated water; a tube connected to the vesseland open at one end to the interior of the vessel, a second tube forsupplying cold water to the vessel projecting through the first tube andspaced therefrom to form an annular passage therebetween. and means forfastening and sealing the inner tothe outer tube at a point outside ofand spaced from the vessel; and a fluid circulating tube connected todischarge into the annular space between said concentric tubes adjacentthe drum. 7

r '7. In a steam and wate drum ofa forced circulation boiler having apump for circulating the water through steam generating tubes connectedfor discharge into the drum; a tube for supplying relativelycold waterto the vessel projecting through the outer tube and spaced from saidouter tube to form an annular passage therebethe drum for positivelycirculating hot water through said passage.

8. In a vessel containing a heated liquid; partition means extendingtransversely of the drum near its bottom sealed to its Walls so as toform a chamber closed off from the remainder of the vessel at the bottomthereof; an outer tube connected to the vessel and open at one end tothe interior of said chamber; a tube for supplying relatively coldliquid to the vessel projecting 10 through said chamber and the outertube to discharge into said vessel and spaced from said outer tube toform an annular passage therebetween below said partition; means forfastening and sealing the inner to the outer tube at a point outside ofand spaced from the vessel; 2, third WARD s. PATTERSON. JULIAN L.BARNES.

